Millimeter of mercury. A millimeter of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high and now defined as precisely 7002133322387415000â 133.322387415 pascals. It is denoted by the symbol mmHg. Although not an SI unit, the millimeter of mercury is still routinely used in medicine, meteorology, aviation, and many other scientific fields. One millimeter of mercury is approximately 1 torr, which is 1/760 of standard atmospheric ...
Vitrectomy is when the eye surgeon removes the vitreous from the inside of the eye. Pars plana vitrectomy is a general term for a group of operations on the deeper part of the eye, all of which involve the removal of some or all of the vitreous â the eyeâs clear internal jelly. Pars plana vitrectomy eye surgery is sometimes done to remove eye floaters or vitreous hemorrhage inside the eyeball. In a vitrectomy, the surgeon âvacuumsâ out the normally clear, jelly-like fluid that fills the inside of the eye, the vitreous humor, with a surgical instrument called a vitrector. The vitrectomy procedure
Vitreous hemorrhage. Vitreous hemorrhage is the extravasation, or leakage, of blood into the areas in and around the vitreous humor of the eye. The vitreous humor is the clear gel that fills the space between the lens and the retina of the eye. A variety of conditions can result in blood leaking into the vitreous humor, which can cause impaired vision, floaters, and photopsia.